1. Field of the Invention
This invention relates generally to a sewer back-up alarm system and more particularly to an early warning system that is triggered into operation before any serious back-up problem occurs.
The use of sewer back-up alarm devices in the clean-out opening portion of a conduit associated with a gravity fed sewer system, is generally well known. Such a sewer back-up alarm device, powered from a 110 volt electrical power supply rather than a battery is disclosed by way of example in U.S. Pat. No. 3,757,316 to Fiorenzo. The sewer back-up alarm device replaces the clean-out opening cap in a sewer outlet conduit in order to detect sewer back-up by means of a sensor. The Fiorenzo patent as well as U.S. Pat. Nos. 3,202,165 and 4,398,186 to Yavicoli and Statz, respectively, teach the use of float operated sensors for detecting the presence of the fluent back-up material in systems which are also powered by 110 volt electrical power supplies. Energization of a lamp indicator under control of the float operated sensor in a sewer back-up alarm system and the extinction of the lamp when the back-up recedes, is also disclosed in the Yavicoli patent. Buzzer types of back-up warning devices are furthermore disclosed in the Fiorenzo patent aforementioned as well as in U.S. Pat. Nos. 4,546,346 and 4,392,128 to Wave et al and Young et al, respectively. According to the Wave et al patent, sewer pipe blockage is detected by a pressure responsive sensor through a detention tank in order to trigger a buzzer type alarm through a pneumatic switch. According to the Young et al patent, the buzzer alarm is triggered when back-up overflow occurs. U.S. Pat. No. 4,091,365 to Allen is also of interest in that it discloses a sewer back-up alarm unit replacing the clean-out cap in the clean-out access opening of a sewer system, wherein the sensor arrangement includes a pivotal float arm. A magnet is attached to the float arm in order to operate a proximity switch when the float arm is displaced to an actuating position by the liquid in the sewer.
It is an important object of the present invention to provide a sewer back-up alarm device of the aforementioned type adapted to be installed in the clean-out access opening of a gravity feed sewer conduit in order to provide an early warning alert with respect to sewer back-up in a more reliable manner.
It is a further object in accordance with the foregoing object to provide an early warning alarm for sewer back-up conditions by means of a device that is easily installed, maintained and monitored with respect to its operating condition.